Question

Two round concentric metal wires lie on a tabletop, one inside the
other. The inner wire has a diameter of 21.0 and carries a
clockwise current of 10.0 , as viewed from above, and the outer
wire has a diameter of 32.0 .

A. What must be the magnitude of the current in the outer wire so
that the net magnetic field due to this combination of wires is
zero at the common center of the wires?